England captain Jos Buttler has been ruled out of the three-match Twenty20 series against Australia and is a doubt for the five one-day internationals that follow.
Buttler, 33, has not played since the T20 World Cup in June because of a calf injury.
In his absence, Phil Salt will captain England for the first time in the T20s, while Harry Brook is in line to step up if needed in the ODIs.
The T20 series begins on Wednesday in Southampton, with the ODIs starting on 19 September.
The visit of Australia is England's first white-ball assignment since they lost in the semi-finals of the T20 World Cup.
Head coach Matthew Mott has since left, but Buttler remained as captain after a review by managing director Rob Key.
Marcus Trescothick is England's interim white-ball coach for the Australia series and the tour of the West Indies in November.
It was announced this week that Test coach Brendon McCullum will take charge of the limited-overs sides, although his combined role does not begin until January.
Buttler was injured in training before The Hundred and sat out the entire competition, along with Lancashire's defeat by Sussex in the quarter-finals of the T20 Blast on Wednesday.
Salt deputised for Buttler as Manchester Originals captain in The Hundred and leads a refreshed T20 squad that includes six uncapped players, including Surrey all-rounder Jamie Overton, who has been called up as cover for Buttler.
Salt has played 31 T20s and 19 ODIs and has established himself at the top of the order for England in white-ball cricket.
The 28-year-old may have taken the wicketkeeping gloves if Buttler was fit, so he could combine keeping with captaincy. Jordan Cox is another option behind the stumps.
Brook will join the ODI squad after a short period of rest following the conclusion of England's final Test against Sri Lanka, which begins on Friday.
The 25-year-old batter has been serving as vice-captain to stand-in Test skipper Ollie Pope this summer.
Brook, a former England Under-19 captain, led Northern Superchargers in The Hundred and would be a candidate as a future skipper of the senior side.
Cox, who has been part of the England Test squad, has been added to the ODI party as cover, to go along with his place in the T20 squad.